def move(n, a, b, c):
    if n == 1:
        print(a, '->', c)
    else:
        move(n-1, a, c, b)
        move(1, a, b, c)
        move(n-1, b, a, c)


if __name__ == '__main__':
    move(3, 'a', 'b', 'c')
